Project will use air pressure waves to remotely detect vehicles, aircraft

Project will use air pressure waves to remotely detect vehicles, aircraft

Researchers at the University of Alaska Fairbanks have launched a three-year effort to develop a new system to remotely detect and assess ground vehicles and low-flying aircraft, including drones.

The Army Research Office is providing $500,000 in funding for the project, which is led by the UAF Geophysical Institute's Wilson Alaska Technical Center. Scientists at the center are researching how to use microphones and seismometers together to detect vehicles and aircraft.

The system will use a process called air-to-ground coupling: When pressure waves travel through the air and then hit the ground, they create seismic waves.

Pressure waves occur when a moving object compresses the air. The compression creates a traveling wave, which is called sound if it's in the human hearing range or infrasound when its frequency is below what humans can hear.

"This research is exciting as it shows the potential to detect and track sources using a set of just two types of sensors in a single portable unit," said David Fee, WATC director. "Traditional geophysical systems often have large footprints and require numerous sensors."

The growing military and civilian use of drones on land and in the air brought renewed attention to long-standing limitations of current detection capabilities.

Detection currently relies on radar and optical sensors. Those technologies can be vulnerable to enemy interference and targeting.

Being able to remotely detect, track and characterize ground vehicles and low-flying aircraft, including drones, can provide battlefield commanders with a significant advantage, according to the project description.

Scientists think the microphone and seismometer combination could offer a solution.

Explosions, rocket launches and meteors cause strong and easily detectable pressure and seismic waves. Pressure waves created by smaller objects, such as armored fighting vehicles or aircraft, are much weaker.

WATC research aims to make those weak signals detectable remotely via a small unit that could be placed by humans or delivered to a site by unmanned vehicle.

"A human would not need to be with the unit once it was deployed," said Kenneth Macpherson, WATC's seismo-acoustic researcher. "The data could be sent to an operational center or listening post."

Macpherson said the technique has several advantages that could complement existing detection systems.

"The hardware is compact and easy to deploy, it does not need to emit any kind of signal that would point back at the user, and it potentially can detect targets at fairly long range," he said. "It will be human-portable, so we can imagine it being deployed outside of a trench or bunker."

The Wilson Alaska Technical Center has extensive experience using seismic and infrasound data. It operates infrasound and seismic arrays worldwide in support of nuclear proliferation monitoring for the Department of Defense.

"Much of the same equipment and expertise related to nuclear explosion monitoring can be used to detect and characterize other signals, such as those produced by ground vehicles and aircraft," Fee said.

The project is funded by the Earth Materials and Processes Program of the Army Research Office.

ADDITIONAL CONTACTS:David Fee, [email protected]; Kenneth Macpherson, [email protected]

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